This invention pertains to packaging and more particularly to a packaging container having readily sealable, mitered end closures.
Packaging for lengthy items has taken many forms. One construction includes a pair of corrugated, laminated paperboard top and bottom U-shaped channels configured for one to fit within the other. In such an arrangement, one form of end cap includes a fitting that inserts into the open ends of the assembly of the U-shaped channels.
The end caps take numerous forms. In one form, a wooden block sized to snuggly fit within the opening is urged, e.g., forced, into the opening. In another configuration, one of the top and bottom U-shaped channels has a notch cut into opposing side walls of the xe2x80x9cUxe2x80x9d, and the xe2x80x9cUxe2x80x9d portion is folded over 90xc2x0. In such a configuration, the ends of the channels are closed by the folded base portion and the side walls of the xe2x80x9cUxe2x80x9d as folded over the adjacent side walls. To further seal the package of this configuration, tape or a like strip-type adhesive sealant is extended over the flaps that are folded over the adjacent side walls. Configurations such as these are disclosed in U.S. Pat. No. 4,976,374 which patent is incorporated herein by reference.
Although there are many different types of package constructions that can be used for safely packaging lengthy items, it has been found that these corrugated U-channels provide a number of advantages over prior known packages. For example, these packages have a high strength-to-weight ratio. In addition, they are made from readily available materials and can be recycled. Moreover, these packages are formed from sufficiently durable materials such that they can, to a limited extent, be used more than once.
One drawback to these materials, however, is the end closure. As described above, in one form, the closure itself is formed, in part, from the package material. However, a sealant such as tape or the like is required to wrap around the package in order to assure that the end closure remains closed. In addition, even when the seal is formed, there may remain an opening at the juncture of the folded over base portion and the cover portion. This, as well as the tape sealant that is used to join the packaging sections provides a weak link, as well as additional materials that are necessary for using such packages.
Accordingly there exists a need for a configuration of packaging container in which the entirety of the end cap or end closure is formed from the packaging material itself. Desirably, in such a packaging arrangement, the end cap or closure is readily sealed using commonly available materials and is sealed in a manner that provides a high degree of structural strength and package integrity. Most desirably, such an end closure provides no gaps at the location of the closure.
A packaging container is formed having integral end closures. The container includes a preformed, rigid base unit of U-shaped cross-section having a bottom wall and opposing side walls and a preformed, rigid cover unit of U-shaped cross-section having, a top wall and opposing side walls. The cover unit is configured so that the side walls of the cover unit are fitted within and embraced by the side walls of the base unit when the base unit and cover unit are assembled as a container.
The base unit forms an end closure for the packaging container. The end closure is formed from a first closure panel extending from and adjacent an end of the base unit, and a second closure panel extending from and adjacent an end of the first closure panel. The base unit and first closure panel are separated from one another by a first fold line. The first closure panel and the second closure panel are separated from one another by a second fold line.
The base unit side walls have mitered corners at a juncture with the first closure panel and the first closure panel side walls having first mitered corners adjacent the base unit. Preferably, the mitered corners are formed complementary to one another so that when folded, a square comer is formed. The first closure panel side walls having second mitered corners adjacent the second closure panel and the second closure panel side walls having mitered corners adjacent the first closure panel. Preferably, once again, the mitered corners are formed complementary to one another so that when folded, a square comer is formed. Most preferred, all of the mitered corners are formed at an angle of about 45 degrees.
The first closure panel is configured for folding generally perpendicular to the base unit bottom wall and the second closure panel is configured for folding generally perpendicular to the first closure panel, generally parallel to the base unit bottom wall and abutting the cover unit top wall.
When folded, the first mitered corners of the first closure panel abut the mitered corners of the base unit side walls, and second mitered corners of the first closure panel abut the mitered corners of the second closure panel. This forms the end closure.
In a present embodiment, the base unit side walls have a height that is about equal to the height of the second closure panel side walls. In this embodiment, the first closure panels have a height that is about one-half of the height of the base unit side walls. In this manner, when folded, the second closure panels insert between the base unit and cover unit side walls to secure the package closed.
Alternately, the second closure panel side walls are formed having second mitered corners. In this configuration, the second closure panel does not insert between the cover unit and base unit side walls, but abuts the side wall mitered corners.
A present packaging container includes two end closures.
These and other features and advantages of the present invention will be apparent from the following detailed description, in conjunction with the appended claims.